1998 Chevrolet Express Van Owner's Manual - Page 264

Thermostat Engine coolant temperature is controlled by a thermostat in the engine cooling system. The thermostat stops the flow of coolant through the radiator until the coolant reaches a preset temperature. When you replace your thermostat, an AC@thermostat is recommended. When to Check Power Steering Fluid It is not necessaryto regularly check power steering fluid unless you suspect there is a leak in the system or you hear an unusual noise. A fluid loss in thissystem could indicate a problem. Have the system inspected and repaired. How To Check Power Steering Fluid When the engine compartment is cool, wipe the cap and the top of reservoir clean, then unscrew the the cap and wipe the dipstick with a clean rag. Replace the cap and completely tighten it. Then remove the cap again and lookat the fluid level on the dipstick. The level should be at the FULL COLD mark. If necessary, addonly enough fluid to bring the level up to the mark. Power :ring ! To prevent contamination of brake fluid, never check or fill the powersteering reservoir with thebrake master cylinder cover off. 6-25